Renewal interest of round window (RW) approaches necessitates further acquaintance of its complex anatomy and its variations. The aim of this work is to study the anatomical characteristics of human RW and the importance of variations in this anatomy to the process of cochlear implantation (CI).Twenty human temporal bones were obtained from cadavers and prepared in a formalin stain. Microdissection was done in 2 phases, phase 1 through facial recess approach and phase 2 external auditory canal approach after dissection of the bone in the area of round and oval window (OW), shape, height and width of the RW were noted. Its distances from OW was measured. Oval (60%), round (25%), triangular (15%) shapes of RW were observed. The average height and width of the RW were 1.91 ± 0.78 mm and 1.37 ± 0.43 mm, respectively. There was a statistically significant correlation (r =0.95, P < 0.001) between the height and width of RW. The distances between the RW and the OW was in the range of 1 –3.5mm. There were no statistically significant differences with regard to gender, or side. Electrode insertion could be challenging in cases where the height and width of the RW are